Chemical Reaction Engineering MCQs

Question 1

A backmix reactor

Accepted Answer

Is same as ideal stirred tank reactor

Answer

Is same as plug-flow reactor

Answer

Employs mixing in axial direction only

Answer

Is most suitable for gas phase reaction

Question 2

For reaction, P + 2 → 3R, molar rate of consumption of P is

Accepted Answer

Half of that of Q

Answer

Double of that of Q

Answer

Same as that of Q

Answer

$${\frac{2}{3}^{{	ext{rd}}}}$$ of that of Q

Question 3

A catalyst

Accepted Answer

Lowers the activation energy of reacting molecules

Answer

Initiates a reaction

Answer

Is capable of reacting with any one of the reactants

Answer

Can not be recovered chemically unchanged at the end of a chemical reaction

Question 4

For the liquid phase zero order irreversible reaction A → B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1 min-1. What will be the conversion for a PFR with a space velocity of 0.2 min-1? (Assume that all the other operating conditions are the same for CSTR and PFR.)

Accepted Answer

0.6

Answer

0.15

Answer

0.3

Answer

0.9

Question 5

Molecularity of an elementary reaction, P + Q → R + S is

Accepted Answer

2

Answer

1

Answer

3

Answer

4

Question 6

The fractional volume change between no conversion and complete conversion, for the isothermal gas phase reaction, 2A → R, is

Accepted Answer

-0.5

Answer

0.5

Answer

1

Answer

1.5

Question 7

A catalyst in a chemical reaction

Accepted Answer

All of the above

Answer

Decreases the activation energy

Answer

Alters the reaction mechanism

Answer

Increases the frequency of collisions of reacting species

Question 8

For a __________ order reaction, the units of rate constant and rate of reaction are the same.

Accepted Answer

Zero

Answer

First

Answer

Second

Answer

Fractional

Question 9

When the reaction is dominated by in-traparticle diffusion, the apparent order of reaction (nD) as measured is related to the true order (n) as

Accepted Answer

$${{	ext{n}}_{	ext{D}}} = \frac{{{	ext{n}} + 1}}{2}$$

Answer

$${{	ext{n}}_{	ext{D}}} = \frac{{	ext{n}}}{2}$$

Answer

$${{	ext{n}}_{	ext{D}}} = {	ext{n}} + 1$$

Answer

None of these